You may be able to use HTML code to try to add the audio in a play block to your mailing, however:

1. I wouldn't know how to make it play automatically2. Our delivery team here has advised against trying to make that happen for fear it would receive complaints3. It would probably not work on a LOT of devices / mail programs.

I'm thinking it may be best to let that one lie, or create a link out to the music so folks can choose to open it up.